Effects of lighting conditions and of hormone replacement on the level of porphyrins in the rat Harderian gland

Abstract

The effects of lighting conditions and/or gonadal secretions on the porphyrins of rat Harderian glands were studied. In female rats, exposure to constant light (= LL) induced a 50% decrease of porphyrin in the Harderian gland. Ovariectomy in these animals caused an increase to levels comparable to those found in intact controls. In males, exposure to constant darkness (= DD) produced a marked increase in the glandular porphyrins together with greatly decreased weights of accessory sexual organs. Further, orchidectomy remarkably increased porphyrin levels in rats kept under conditions of LL or DD. Administration of testosterone propionate to castrated male rats significantly decreased the porphyrin contents in the gland, although estradiol benzoate and progesterone treatments had no effect on the levels. Similar results were obtained in female rats.

Postnatal development of the harderian gland in the Syrian golden hamster (Mesocricetus auratus): A light and electron microscopic study

“…The HG has been used increasingly a s a model of porphyrin biosynthesis (Tomio and Grinstein, 1968;Margolis, 1971;Ulrich, 1974;Jones and Hoffman, 1976;Shirama et al, 1981Shirama et al, , 1987Lin and Nadakavukaren, 1982;Thompson et al, 1984;Spike et al, 1988Spike et al, , 1990. However, in spite of these studies, the mechanism of release of porphyrin into the lumen remains controversial.…”

Ultrastructural study of lamellar and nucleolus‐like bodies in the harderian gland during postnatal development of the hamster (Mesocricetus auratus)

“…The Harderian gland (HG) is a compound tubule+ alveolar gland of animals that possesses a nictitating membrane, located in the posterior portion of the orbit. The function of this gland has not been clearly established, but to date most of the available data seem to indicate that it is a component of a system that involves light, the pineal gland, and the reproductive organs (Wetterberg et al, 1970;Reiter and Klein, 1971;Diioria and Nadakavukaren, 1984;Shirama et al, 1987). In the golden hamster, the HG displays sexual dimorphism which is influenced by gonadotrophins and steroid hormones (Woolley and Worley, 1954;Hoffman, 1971; Nadakavukaren, 1972, 1973;Lin and Nadakavukaren, 1979;Sun and Nadakavukaren, 1980;Nadakavukaren and Lin, 1983;Spike et al, 1985Spike et al, , 1986Payne et al, 1985).…”

Proteome Profiling in the Rat Harderian Gland

“…The role of porphyrins in the HG and for the organism per se has not been elucidated yet and is mainly speculative although sexual dimorphism and gonadal endocrine regulation of porphyrins − have been reported. Adaptation to season and light may represent another possible function physiological of porphyrins in the HG. , Providing general proteome information on porphyrin metabolising and handling enzymes was therefore another goal of the study.…”

“…Adaptation to season and light may represent another possible function physiological of porphyrins in the HG. 25,26 Providing general proteome information on porphyrin metabolising and handling enzymes was therefore another goal of the study.…”